![](https://images.gutefrage.net/media/default/user/11_nmmslarge.png?v=1551279448000)
![](https://images.gutefrage.net/media/default/user/15_nmmslarge.png?v=1551279448000)
Flächeninhalt des Quadrats = Flächeninhalt des Kreises
AQuadrat = a × a = 20cm × 20cm =400cm²
AKreis = pi × r² = 400cm² => r² = 400cm²/pi => r = (400cm²/pi)½
Flächeninhalt des Quadrats = Flächeninhalt des Kreises
AQuadrat = a × a = 20cm × 20cm =400cm²
AKreis = pi × r² = 400cm² => r² = 400cm²/pi => r = (400cm²/pi)½